[1
] HVTN, Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center,
Seattle, WA, USA
[2
] Desmond Tutu HIV Centre, University of Cape Town, P.O. Box 13801, Mowbray, 7705 Cape
Town, South Africa
[3
] South African Medical Research Council, Francie van Zijl Drive, Parowvallei, Cape
Town; PO Box 19070, 7505 Tygerberg, South Africa
[4
] HVTN, Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center,
1100 Fairview Avenue North, Mail-stop E3-300, Seattle, WA, 98109, USA